FCW carbon fiber mag extension for the Remington 870/1100/11-87/Versamax and V3 12ga shotgun. Adds 6 rounds of 2-3/4� shells. Adds approx. 14 1/2 in length and 4.50 oz in weight. Comes with our SS extreme duty spring and wrench. We recommend use of a support clamp with this extension and can be purchased separately .